Apparatus for cracking hydrocarbons



E. C. HERTHEL APPARATUS FOR CRACKING HYDROGARBONS swept. 4, 1928,

Filed June 11, 1927- Patented Sept. 4,

EUGENE c.l Hammer., or CHICAGO, ILLINOIS, AgssIGNoii fro merma gamme con- PATENT- oFFicE.

rm, or NEwYoax, N.. Yr, A colaroiurr'IoN.or1

. Arrmrus Non ca AcKING EYDRocAnBoNs.

Application led June 11, 1927'. Seriallp. 198,246.

" his invention relates toimprovexnents in the distilling underv pressure of heavier and higher boiling hydrocarbon oils, such as gas oil, for the prductiontherefrom of lighter and lower boiling hydrocarbon oils, such as gasoline and gasoline-containing distillates.

In one advantageous method of carrying "A out such pressure distillation, a. chargefof heavier oil is circulated in a still made up of a bulk supply drum and a battery of heating tubes through1 which the oil is circulated from and back to the bulksupply drum, a

'bed ofrfinely divided absorbent or filtering.

. materialbeing arranged in the bulk supply drum so that the circulating unvaporized4 oil is compelled to pass therethrough, vapors being separated from'the circulating oil vas' it is dischargedinto the `bulk supply drum from the battery of heating tubes. In such v operation, cracking continues inthe circusy lating charge of Ioil as long as it is at a cracklng temperature, and as a consequence there is a tendency to separation of vapors 'and gases. from the circulating oil after it has passed through the bed of filtering or I'ab- J sorbent material and before it enters the ybatvtery`of heating tubes. Likewise,'th'e1fe is. a tendency to revaporization of reflux condensate returned and admixedwith the` circu' lating oil which has passed through the bed v of filtering or absorbent material. The bed of filtering or-r` absorbent material in the still assists'in promoting complete separationof vapors from the oilv discharged into thebulk supply' drum'from the battery of heating.

tubes, but nevertheless therelissom'e tend. ency' toward the fornrati-onof vapors intthe circulating oilafter it has passedfthrough the bed'ofjiltering or absorbent"' material.

To the extent. that thesevapors are' com- `pelled to pass through the battery of heat- 'lng tubes, there is -a tendencyto overcracliijigof constituents otherwise -suitable as 'components of the desired-l product. To the extent that these vapors are conned beneath the bed o`fv ltering or absorbent mateingioi after it has passed -throughthe bed arated from the `hot oil of filtering or .absorbent material is reduced.V

and whereby any vaporsfthat may so be formed are taken oii with the vaporspse'p-e l 'discharged into the bulk supplydrum. -U

The invention will be further ,described -in connection with `the accompanying drawings wlrich illustrate, ina diagrammatic and conventional manner, a pressure still em# body1ng`-the inventionand adapted for the practice of the' invention. Inythe accompanying drawings:

F ig. l is an elevation, partly section still system,

' Fig. 21s a sectional view of the still l I shown in Fig. l, and

. Fig .3, is an enlarged fragmentary view, in section, of one form of supportfor the benli1 of filtering or absorbent material in the sti."'

ings comprises'a .bulk -supply drum 1, a battery of heating tubes2, and circulating con- The pressure still-illustrated in the'drawI-.I4

vandwith parts broken away, ofl a pressure nections 3, 4 and including a circulating pump 6. A beddskof filtering or yabsorbent material 7, such as fullers earth, is arranged within the bulk supply drum on a support 8. This bedof filtering or absorbent material extends entirely across the bulk. supply drum between the -discharge circulating connection 3 and the return circulating connections 5, in eiect dividing the space below the normal liquid level in the bulk-supply druminto two, compartments from one of which oil is'circulated to the battery of heating tubes andinto the other of which' the oilfrom the battery of heating tubes is discharged, oiL

` assing from th last to the first through the ed of filtering orfabsorbent material.

Vapors from the bulk supply drum enter the reflux tower 9, arranged above the bulk supply drum, through connection 10. Va-

pors from -the' reflux tower pass'through connection 11 4and valve '12, by which the pressure in the system 'may be regulated, to the condenser 13. This condenser discharges intofthe receiver 14. The'distil'l'ate product is discharged from the receiver throughconnejction 15 and uncondensed vaporsand gases through connection l16. Fresh oil to be su plied to the operation lis introduced intot e iosupper end of' thereii-ux torwer` through connection 17. Redux condensate .and admixed unvaporized -fresh oil dow from the lower end of the redux tower back to the pressure pitch-laden oil. or tar durin operation, an

connection 20 is provided or pumping out the still at the end of a run and for initially charging it at the beginning of a run. A part of the fresh oil supplied to the operation may be introduced through the bearings of the circulating pum 6 forv cooling and lubrication by means o connection 21. In operation, it isl advantageous to regulate the supply of fresh oil and the discharge of pitch-laden oilto maintain the concentration of pitch constituents below saturation in the oil enteringthe battery of heating tubes, as described in Letters Patent No. 1,598,136, issued to the Sinclair Refining Qompany, August 31, 1926, on my applica-v l the bed of absorbent or v16 to 30 After being One suitable form of the support' 8 is illustrated more in detail in Fig. 3. As.

shown, this support comprises three screens and two perforated plates, a line screen be# lons per hourand pitch-laden oil or tar- Withdrawn at a rate upwards of 1,500 gallons per hour.

The pressure in the system may, for example, be maintained in the neighborhood of from 100 to 150 pounds per square inch.

In. accordance with the present invention,

- vents iare arranged between the upper" part of the space be ow the bed ofiltering or absorbent material and the s ace in the upper part ofthe bulk supply rum above the normal liquid level therein. In the pressure still illustrated, these vents comprise a pair lof tubes 22 extending through the support 8 for the bed of dltermg or absorbent material into the vapors ace in the upper part of .the bulk supply as described, t ese vents permit the escape from beneath the support 8I and the bed of dltering or absorbent material 5 7, of any `vapors separated from the oil which has passed through'the bed of filtering material, into the vapor space in the upper part rum 1. In operation,

of the bulk supply drum 1 from which'they pass together with. va ors separated from the -hot oil dischar ed lnto the bulk supply drum above the beof filtering or absor nt material to the redux tower 9. Similarly, any vapors separating from redux condensate Oor fresh oil entering the still throu h connection 18 which are not carried with t e circulating oil may escape through these vents. T e provision of these vents ,also assists in equalizing, o r in making more nearl equal, the pressuresr in ,the bulk supply. rum above and below the bed of absorbent orfiltering material and thus also 4 assists in reducing the tendency to vaporization below the bed of filtering or absorbent material by reducing any pressure did'erential that may exist. In operation, it is advantageous to avoid too rapid forcm of the circulation through the battery of eating tubes.

I claim: I

1. In a pressure still comprising-a bulk suppl drum in which a bed of dlterin or absor ent material is arran entirely across the drum and elow the normal liquid level therein, a battery of heating tubes and connections for circulating .oil from the spacein the bulk supply drum beneath the bed of filtering or absorbent material through the battery of heating tubes and back to the space in the bulk supply drum above the bed of filtering or absorbent materia-l, venting means connecting the upper part of the space beneath the be of filtering or absorbent material and the 4space in the upper .part of the bulk supply drum above the normal liquid level therein; 2.A In a pressure still comprising a bulk supply drum in which a bed"of 4filtering or absorbent material is arran d extending, entirely across the drum and elow the normal li uid level therein, a battery of heatin tu and connections for circulating' oi from the space in the bulk supply drum beneath the bed of filtering or absorbent material through the battery of heating tubes and back to the s ace ,in the bulk su ply drum above the be of filtering ror absorbent material, a redux tower, connections for conducting vapors from the upper part of the bulk supply drum thereto and liquid return connections from the redux tower discharging beneath the bed of filtering or absorbent material, venting means connectingthe uppart of the space `beneath thebed ofv liltenng or absorbent 'material and the s ace in rthe upper part of the bulk supply rum above the normal li uid level therein. In testimony {wheilkeo j have subscribed my name. l i v EUGENE o. HER'rHEny d exten ingl lOl 

